This disclosure relates generally to identifying interchangeable instruments, and more particularly to automatically detecting and identifying interchangeable instruments for use in with an electromagnetic surgical navigation and/or tracking system.
Electromagnetic tracking systems have been used in various industries and applications to provide position and orientation information relating to instruments or objects. For example, electromagnetic tracking systems may be useful in aviation applications, motion sensing applications, retail applications, and medical applications. In medical applications, electromagnetic tracking systems have been used to provide an operator (e.g., a physician, surgeon, or other medical practitioner) with information to assist in the precise and rapid positioning and orientation of an instrument (such as a medical device, implant, tool, or other implement) located in or near a patient's body during image-guided surgery. The electromagnetic tracking system provides position and orientation information for an instrument with respect to the patient's anatomy or to a reference coordinate system. The electromagnetic tracking system provides intraoperative tracking of the precise location of the instrument in relation to multidimensional images of a patient's anatomy. As the instrument is positioned within or with respect to the patient's anatomy, the displayed image is continuously updated and tracked to reflect the real-time position and orientation of the instrument being used.
The known physical size and shape of the instrument can be used to calculate the location and orientation of each portion of the instrument, which is then used, in turn in generating and displaying the real time position of each portion of the instrument. The combination of the image and the representation of the tracked instrument in real time provide position and orientation information that allows a medical practitioner to manipulate the instrument to a desired location with an accurate position and orientation and display that location along with other reference structures or anatomy.
When different instruments are used with electromagnetic tracking systems, the system must be calibrated to the known physical size and shape of the particular instrument being used so it will be properly be represented on the display. Hall-effect sensors in a receiver and permanent magnets organized in a particular pattern in the instruments have been used in the past to detect and identify the different instruments being used during surgical procedures.